Calender vibration eliminator



J. L. MURRAY 3,111,894]

CALENDER VIBRATION ELIMINATOR Nov; 26,1963

2 Sheets-Sheet 1 Filed April 17, 1962 INVENTOR. KSON L.MURRAY JAC BY Y LULLAMDWW PATEN T AGENT Nov. 26, 1963 J. L. MURRAY 3,111,894

CALENDER VIBRATION ELIMINATOR Filed April 17, 1962 2 Sheets-Sheet 2 INVENTOR. JACKSON L. MURRAY Y PATEN T AGENT United States Patent 3,111,894 CALENDER VHBRATHON ELKMINATQR Jackson L. Murray, Oakland, Md., assignor to West Virginia Pulp and Paper Company, New York, N.Y., a corporation of Delaware Filed Apr. 17, 1962, Ser. No. 188,121 7 Claims. (Cl. 100-162) This invention relates generally to an apparatus for eliminating the vibration in superimposed rotating rolls and particularly to the elimination of changes in a paper 'web which is caused by the vibration of the metallic rolls in a calender stack on a paper machine.

Calender stack vibration, when associated with a paper machine, usually causes variations in the caliper of the paper web. The caliper variations are visibly apparent in the form of bars, glossy strips where the calender rolls vibrate toward the paper web and dull strips where the calender rolls vibrate away from the paper web, across the paper web, and are the result of sudden changes in the calendering action. Machine direction caliper variations resulting from calender stack vibration frequently result in a rejection of the paper web by the user because of the substandard surface quality. Printing, folding, and other general physical properties of the paper web are altered by the irregular calendering action during the vibration of the machine calender stack.

Vibration problems are unique to machine calender stacks made up entirely of superimposed metallic rolls. This is to be contrasted with supercalender stacks having superimposed metallic rolls separated by cotton or paper rolls in which no vibration occurs. It is to be understood that calender stack as used herein refers to a calender composed entirely of a plurality of superimposed metallic rolls. Calender stack vibration is not only detrimental to the paper web, but is also detrimental to the calender rolls. Vibration, if allowed to continue, damages the surfaces of the metallic calender rolls and the bearings of the metallic calender rolls.

In the past, attempts to eliminate calender stack vibration have included means directed toward bending the ends of the calender rolls upwardly by means of an imposed force, such as could be obtained by air diaphragms and pivot arms that are deployed to push upwardly on the bearings of the calender rolls. Although the bending did reduce vibration tendencies, the paper web was calendered more in the middle portion than in the outer portions, causing caliper differences in the cross machine direction. Cross machine caliper differences result in a sub-standard paper web and are usually reason enough for rejection of the paper web by the user. Other prior attempts to eliminate calender vibration employed mechanical vibration dampeners. The dampeners were tuned to have the same frequency as that imposed on the calender rolls. The force created by the dampener opposed the force causing the vibration, resulting in a socalled balanced system. Changes in the frequency imposed on the calender stack resulted in a so-called unbalanced system in which the dampeners were no longer effective in preventing calender stack vibration. Unfortunately, changes in paper machine speeds or in the number of calender rolls altered the imposed frequency of the calender stack, unbalancing the system. The number of metallic rolls employed in a calender stack is dependent upon the degree of calendering action desired, and is widely variant for different grades of paper.

Experience indicates that the occurrence of calender stack vibration is spasmodic. Any one calender stack will operate free of vibration problems for various periods of times and then, without Warning, will begin vibrating. Unlike the prior systems, the preferred em- "ice In addition, the invention eliminates vibration, regardless of the imposed frequency causing the vibration.

Also, the elimination of the vibration is accomplished without effecting the action of the calender stack, such as, caliper changes in the cross machine direction.

Further, the invention is designed to be easily added to existing calender stacks.

Still further, the invention is widely applicable to many systems having superimposed metallic rolls that are troubled with vibration problems.

Many additional advantages will appear in the following detailed description considered in connection with the drawing in which:

FIG. 1 is a perspective view of the type of calender stack that employs the invention.

FIG. 2 is an enlarged fragmentary elevational view of the calender stack set forth in FIG. 1 showing the features of the invention in greater detail.

FIG. 3 is an enlarged fragmentary elevational view of the calender stack shown in FIG. 2 with certain elements removed.

FIG. 4 is an elevational view of the portion of the calender stack shown in FIG. 3 with certain elements removed.

FIG. 5 is an enlarged fragmentary view taken generally along the line 55 of FIG. 4.

From FIG. 1, notice that the bottom-most roll or king roll It is of larger diameter than the superimposed metallic rolls 11. The king roll is carried at its outer portions by the bearings 12 which are mounted on the lower portion of the upright side plates 13. A driving gear 14 is attached to and rotates with the king roll 10. The driving gear 14 is driven by the pinion gear 15 which is connected to a suitable drive means (not shown). The superimposed metallic rolls 11 are driven by the king roll 10 through frictional contact in the nips. The upright side plates 13 terminate into the channel members 16 and are spaced apart by the cross plate 17. The superimposed metallic rolls 11 are carried by the bearings 18 which are formed by the outer parts of the carrying arms 19. The opposite or inner parts of each of the carrying arms 19 is provided with a pin 25) which is engageable with the U-shaped arms 21. The U-shaped arms 21 are rigidly attached in spaced superimposed arrangement to the upright side plates 13.

In normal operation of a calender stack in a typical paper machine, the paperrnaker, depending upon the amount of calendering action desired, varies the number of superimposed metallic rolls 11 on the calender stack. In the particular embodiment shown, the rolls are removed by extracting the pin 20 from the carrying arms 19. It should be apparent that the carrying arms 19 and the superimposed metallic rolls 11 are removed as a unit after pin 20 extraction.

Calender stacks are loaded externally by means of a force being applied downwardly on the top metallic roll 11a. In this particular embodiment, the loading system comprises bellows 22 and rods 23. The bellows 22 is pressurized to force the rods 23 downwardly. The opposite ends of the rods 23 are connected to the outer parts of the carrying arms 19 of the top metallic roll 11a. The pressure into the bellows can be adjusted by standard means -(not shown) to apply a predetermined load to the calender stack. The force creates a pressure in the nips of the metallic rolls, and thus the calendering action can be altered by varying the applied force.

The calender stack thus far described is intended to be an illustrative example of an open calender stack in which the metallic rolls are carried on arms outside of the calender framing. Notice in FIG. 1 that the superimposed metallic rolls 11 are positioned by the carrying arms 19 and the U-shaped arms 21 outside of the upright support plates 13. In A frame or closed calender stacks, the superimposed metallic rolls are mounted in bearings carried between a pair of upright support plates. It is to be understood that this invention is applicable to open and closed calender stacks. The industry has shown preference to the open calender stacks, and for this reason the applicant has chosen an open calender stack as his preferred embodiment.

Referring to FIGS. 1 and 2, the topmost roll 24 of the calender stack is designed and deployed to prevent the damaging after-effect to the paper web of calender stack vibration. The topmost roll 24 has a resilient surface, and is preferably a rubber surfaced roll, containing a metallic core. The metallic core strengthens the resilient roll 24 and reduces the possibility of extensive deflections caused by the weight of the roll and by exterior forces. In operation, the resilient roll 24 prevents vibration in the calender stack when in contact with the top metallic roll 110. When used as described in the following description, the resilient roll 24 will quickly and positively nullify the vibration of a paper machine calender stack.

The paper web 25 is depicted in FIG. 1 as being introduced into the calender stack between the resilient roll 24 and the top metallic roll 11a. The paper web 25 then travels through the length of the calender stack in standard serpentine manner. The exact travel of the paper web can be determined by the arrows that indicate the rotation of the superimposed metallic rolls 11. The resilient roll 24 will cooperate with the calender components to prevent vibration when the paper web travel enters the calender stack in the nip formed by the top metallic roll 11a and the resilient roll 24.

As shown in this particular embodiment, the resilient roll 24 is in the topmost position on the calender stack. The resilient roll 24 could be stored nearby and trans ferred to the calender stack when vibration occurred; however, the ability of the resilient surfaced roll to remove vibration is accomplished in a way that is most convenient when deployed as shown in FIGS. 1-5. Little time is expended to stop calender stack vibration by lowering the resilient roll 24 into contact with the top metallic roll 11a. Furthermore, the resilient roll 24, since it is used only during the periods of vibration, is not subjected to undue wear. subjecting the resilient roll to continual use, as would be the case if it was continually running against the surface of the top metallic roll 1111, would also subject the resilient roll to possible damage in the event of a paper web breakage within the calender stack. In such cases, the paper web tends to wrap around the calender rolls building up surface irregularities which would impose a substantial vibration in the calender stack and damage the relatively soft surface of the resilient roll.

Referring to FIGS. 1 and 2, the resilient roll 24 is in topmost position and is connected through the rod 26 to the bellows 27. Unlike the operation of the loading system for the top metallic roll 11a, the control system for the topmost resilient roll 24 in this preferred embodiment forces the topmost resilient roll downwardly only when calender stack vibration occurs. When there is no vibration in the calender stack, the bellows 27 is loaded so that the rod 26 is forced upwardly thereby raising and holding the resilient roll 24 above the surface of the top metallic rolls 11a. When vibration is observed, the bellows 27 is energized by a convenient means (not shown) to push the rod 26 downwardly and thereby forces the resilient roll 24 against the surface of the top metallic roll 11a. The contact between the rolls dampens the 4 vibration of the calender stack and removes the associated caliper changes in the paper web.

In order to locate the resilient roll 24 in the topmost position as shown in FIGS. 1-5, a convenient means should be provided to bring the resilient roll 24 up to a surface speed substantially equal to the surface speed of the top metallic roll 11a. Failure to bring the resilient roll 24 up to speed before contacting the top metallic roll 11a would cause the paper web to fracture.

Referring to FIG. 3, the resilient roll 24 is shown away from the top metallic roll 11a. The drive rolls 28, 29, preferably resilient surfaced, are rotating on the surface of the top metallic roll 11 and the resilient roll 24, respectively. FIG. 3 is illustrative of the preferred embodiment as deployed during the phase of bringing the surface speed of the resilient roll 24 up to substantially equal the surface speed of the top metallic roll 11a. A carrying frame member 30 is held in position by the pins 2%. Referring to FIG. 4, the carrying frame member 30 is removed showing that the drive rolls 28, 29 are rotatably carried by a holder plate 31 which is connected to the piston rod 32 of a double acting fluid cylinder 33. From FIG. 5, notice that the double acting fluid cylinder 33 has the blank end rigidly attached to the carrying frame member '39. By loading the rod end of the double acting fluid cylinder 33, the holder plate 31 and the drive rolls 28, 29 are moved toward the top metallic roll 11a and the resilient roll 24. The movement to the right, as shown in FIGS. 3-4, brings the drive rolls 28, 29 into contact with the top metallic roll 11a, and the resilient roll 24, respectively. The drive rolls 28 and 29 are in superimposed rotating contact so that the drive roll 29 is driven by the drive roll 28 with no slippage occurring therebetween. The drive roll 28, when to the right as shown in FIGS. 3-4, is driven by the top metallic roll 11a. By bringing the drive rolls 28, 29 into contact with the top metallic roll 11a and the resilient roll 24, respectively, a means is provided for driving the resilient roll 24 to a surface speed substantially equal to the surface speed of the top metallic roll 11a. Notice from FIG. 5, that the drive rolls 28, 29 extend inwardly a short distance from the carrying frame member 30. As a result, the drive roll 23 does not contact the paper web that wraps the top metallic roll 110, thus overcoming the possibility of scufling the paper web during the contact between the drive roll 255 and the top metallic roll 11a.

The resilient roll 24 is normally carried away from the top metallic roll 11a by the holding action of the bellows 27 acting through the rod 26 and the drive rolls 28 and 29 are normally held to the left as viewed in FIGS. 3-4 away from the surface of the top metallic roll 11a and the resilient roll 24 by the fluid cylinder 33. When calender stack vibration occurs, the double acting fluid cylinder 33 is exhausted on the piston rod end and loaded on the blank end, which forces the drive rolls 28 and 29 against the surface of the resilient roll 24 and the top metallic roll 11a, respectively. The resilient roll 24 is driven to a surface speed substantially equal to the surface speed of the top metallic roll 1 1a by the rotating cont-act obtained between the rolls as explained above. Once up to speed, the double acting fluid cylinder 33 is loaded on the rod end to move the drive rolls 29 and 28 away from contact with the resilient roll 24 and the top metallic roll 11a, respectively. The bellows 27 is energized, lowering the resilient roll 24 down upon the top metallic roll 11a as shown in FIG. 2. The time span for the entire operation is very short, and the resilient surfaced roll 24 is still rotating at substantially the same speed as the top metallic roll 11a when contact occurs. Alternate means for bringing the resilient roll 24 up to speed are possible that still reside in the area of the invention. For example, an electric motor could be mounted in proximity with the resilient roll, bring the resilient roll up to speed, and then be disengaged prior to lowering the resilient roll into contact with the metallic roll.

When it is desired to have less calendering action, one or more of the metallic rolls 11 are removed from the calender stack. The carrying arms 19 are separated from the U-sh'aped arms 21 by extracting the pin 20. The resilient roll 24 must be lowered to compensate for the removed metallic rolls. The pins 20 joining the top metallic roll 11a and the resilient roll 24 to the U-shaped arms must therefor serve a dual purpose. First, as explained above, the pins are extracted to remove the rolls. Second, as an additional purpose, the pins 20 are adapted to position and positively hold the carrying frame member 30. A method of designing the pins 20 to perform the positioning function and the removing function should be evident to those having ordinary skill and will not be described in detail herein. As an example, the pins could be formed from specially designed bolts that are locked in place with lock nuts. The rods 23 and 26 are elongated to compensate for the lower position of the top metallic roll 11a, and the resilient roll 24 by either employing longer rods or by employing rod extensions.

When the resilient roll 24 is moved to another position on the upright side plates, the pins 20 are extracted, thus removing the carrying frame member 3% and the carrying arms 19 of the resilient roll 24-. Both assemblies are relocated in the new posit-ion by inserting the pins 20 into the corresponding U-shaped arms 21 after the carrying arms 19 and the carrying frame member 30 have been positioned in alignment with the hole provided in the U-shaped arms.

As stated above, calender stack vibration resulting in the changes in caliper in the paper web is not an ever present feature, but appears randomly during the operation. As a result of this unique property, it is advantageous that the vibration removing resilient roll 24 be ever present on the top of the calender stacks as indicated in FIGS. 1-5 where the vibration can be quickly and positively halted. The invention not only provides a means for removing vibration but also a means for increasing the life of the vibration removing resilient roll 24 by employing a means for suspending the resilient roll 24 above the calender stack during periods in which no vibration occurs.

It should be obvious in view of the above to those familiar with the art that the resilient roll could be permanently affixed as the topmost roll. These and many other modifications are possible, all of which are intended to be included which fall within the scope of the following claims.

I claim:

1. A calender stack on a paper machine comprising a multiplicity of superimposed rotating metallic rolls having a top metallic roll forced downward for loading the calender stack, a topmost resilient surfaced roll, means for bringing the topmost resilient surfaced roll into contact with the top metallic roll upon the occurrence of calender vibration, and means for bringing the topmost resilient surfaced roll up to substantially synchronous surface speed with the surface speed of the superimposed rotating metallic rolls before bringing the topmost resilient surfaced roll into contact with said metallic rolls.

2. A calender stack on a paper machine comprising a pair of upright side plates, a multiplicity of superimposed metallic rolls rotatably carried between the pair of upright side plates, said lowermost metallic roll of the superimposed metallic rol'ls being driven, means for forcing the top metallic roll downwardly for loading the calender stack, a topmost resilient surfaced roll rotatably carried between the pair of upright side plates engageable with the top metallic roll upon the occurrence of calender vibration, and means carried by the upright side plates for bringing the topmost resilient surfaced roll up to substantially synchronous surface speed with the surface speed of the superimposed metallic rolls before bringing the topmost resilient surfaced roll into contact with the superimposed rolls.

3. A calender stack on a paper machine comprising a pair of spaced upright support plates, a multiplicity of pairs of carrying arms pivotably mounted on the pair of upright support plates in spaced superimposed relationship having outer portions extending away from the upright support plates, said pairs of carrying arms in horizontal alignment, metallic rolls rotatably carried in superimposed horizontal relationship by the outer portions of the pairs of carrying arms, a topmost resilient surfaced roll rotatably carried horizontally by the outer portion of the topmost pair of carrying arms, means for bringing the topmost resilient surfaced roll into contact with the superimposed metallic rolls upon the occurrence of calender vibration, and means for driving the topmost resilient surfaced roll up to substantially synchronous surface speed with the surface speed of the superimposed metallic rolls before bringing the topmost resilient surfaced roll into contact with the superimposed rolls.

4. The apparatus according to claim 3 in which the means for driving the topmost resilient surfaced roll comprises a plurality of drive rolls mounted on the outer portion of the carrying arms in proximity of the topmost resilient surfaced roll, and means for moving the plurality of drive rolls against the surface of the top metallic roll and the topmost resilient surfaced roll, thereby driving the topmost resilient surfaced roll up to substantially synchronous rotative surface speed by the rotating contact between the drive rolls and the top metallic roll.

5. In a calender stack on a paper machine having a multiplicity of calender rolls, all of which are metallic rolls, said metallic rolls being in direct rolling engagement with one another with a paper web interposed between said metallic rolls during the calendering operation, the improvement comprising a topmost resilient roll for eliminating calender stack vibration and the resultant caliper variations in the paper web.

6. In a calender stack on a paper machine having a multiplicity of calender rolls, all of which are metallic rolls, said metallic rolls being in direct rolling engagement with one another with a paper web interposed between said metallic rolls during the calendering operation, the improvement comprising a topmost resilient roll for eliminating calender stack vibration and the resultant caliper variations in the paper web, and means for lowering the topmost resilient roll into contact with the calender r011 immediately beneath upon the occurrence of calender vibration.

7. In a calender stack on a paper machine having a pair of spaced upright support plates, a multiplicity of carrying arms pivotably mounted on the pair of upright support plates in spaced superimposed relationship with outer portions extending away from the pair of upright support plates, and a multiplicity of calender rolls, all of which are metallic rol-ls carried in superimposed relationship by the outer portions of the carrying arms, said metallic rolls being in direct rolling engagement with one another with a paper web interposed between said metallic rolls during the calendering operation, the improvement comprising a topmost resilient roll for eliminating calender stack vibration and the resultant caliper variations in the paper web, said topmost resilient roll being carried by the outer portions of a pair of said carrying arms, and means for lowering the topmost resilient roll into contact with the calender roll immediately beneath upon the occurrence of calender vibration.

References Cited in the file of this patent UNITED STATES PATENTS Schurmann July 25, 1922 

5. IN A CALENDER STACK ON A PAPER MACHINE HAVING A MULTIPLICITY OF CALENDER ROLLS, ALL OF WHICH ARE METALLIC ROLLS, SAID METALLIC ROLLS BEING IN DIRECT ROLLING ENGAGEMENT WITH ONE ANOTHER WITH A PAPER WEB INTERPOSED BETWEEN SAID METALLIC ROLLS DURING THE CALENDERING OPERATION, THE IMPROVEMENT COMPRISING A TOPMOST RESILIENT ROLL FOR ELIMINATING CALENDER STACK VIBRATION AND THE RESULTANT CALIPER VARIATIONS IN THE PAPER WEB. 